The online concert is the replacement for her acoustic tour that was canceled earlier this year. The tour was originally meant to play throughout Japan between early September and late November. The live finale of the tour was to be held at the Christ Shinagawa Church Gloria Chapel in Tokyo on 11/27/20. That show will still be held but sans audience. It will also be broadcast worldwide across the internet.
The official name for the concert is "Aimer Live at Anywhere 2020 in Christ Shinagawa Church."
Tickets are 3600 yen. The stream starts at 1730 hours JST on 11/27/20 and the show itself starts at 2000 hours JST. A rebroadcast for those in Japan will be available for viewing until 2359 hours on 11/29/20.
Please visit https://www.aimer-web.jp/live/ for details. Tickets can be purchased by those in Japan at https://yahoo.jp/IgY70W
Those in mainland China should purchase from https://live.bilibili.com/blackboard/activity-Aimer_Live_at_Anywhere2020.html?is_live_webview=1. Tickets are 210 yuan.
Those in any other part of the world can purchase from https://livefrom.events/aimer. Tickets are $30, so it's actually slightly cheaper than if you had bought it in yen (but without rebroadcast).
Goods are purchasable for those in Japan at https://aimer-store.jp/ and outside of Japan at http://www.asmart.jp/aimer. Expect a long delay for those not in Asia; my packages have been showing up routinely after two months due to going via seamail between Japan and the United States.